Automatic air-valve



(Model.)

0. JENKINS.

AUTOMATIC AIR VALVE.

Patented Aug. 27, 1889.

W/TNEEEEE.

UNITED STATES PATENT OFFICE.

CHARLES JENKINS, OF BOSTON, MASSACHUSETTS.

AUTOMATIC AIR-VALVE.

SPECIFICATION forming part of Letters Patent No. 409,685, dated August27, 1889.

Application filed November 15, 1887. Serial No. 255,185. (MocleL) To allwhom it may concern.-

Be it known that I, CHARLES JENKINs, a citizen of the United States, ofBoston, in the county of Suffolk and State of Massachusetts, haveinvented a new and useful Improvement in Automatic Air-Valves, of whichthe following; is a full, clear, and exact description, reference beinghad to the accompanying drawings, forming a part of this specification,in explaining its nature.

The invention relates to an automatic airvalve particularly adapted foruse upon steam-radiators and adapted to be operated by variation in thetemperature.

In the drawings, Figure 1 is an elevation of the valve. Fig. 2 is acentral section thereof, representing the valve as closed. Fig. 3 is acentral section representing it as open. Fig. 4 is a centrallongitudinal section representing a slightly different form ofconstruction.

Referring to the drawings, A is the body of the valve. It has thevalve-chamber a, which has three openings-first, the inlet a in theserew-teat a second, the outlet a formed in the nozzle a, which has aninterior screwthread a and a large hole a, formed in the neck M, whichhas an interior screw-thread a which receives the screw-plug a and anexterior screw a to hold the cap a.

About the outlet-passage a in the valvechamber a is a raised valveseatl3, and be tween this valve-seat and the screw-pluga is a valve O. Thisvalve is represented in Figs. 2 and 3 as attached to the screw-plug byfitting a recess therein, and it is also represented as being quitelong. It is therefore a valve and stem combined. The entire device istherefore an air-valve or steam-trap of the sort familiarly known as arod-trap, in which the opening and closing of the valve are broughtabout by a difference in the modulus of expansion at a givensteam-tempe1= ature between the valve-stem and the shell of the valve towhich the valve-seat is attached. It is essential for this purpose thatthe valve-stcm should be comparatively inflexible and refractory at thetemperature to which it is exposed; and in order to make the wholestructure as small as possible it is desirable that there should be aconsiderable difference between the modulus of expansion of thevalve-stem at a given temperature and that of the shell of the valve towhich the valve-seat is attached. Various compounds have been hithertoused for what is known as compression-packing or elastic steampacking,not including in this term the kinds of packing known as pure packing,plain packing, and fibrous or mixed packing, but only such as aregenerically described as crude, burned, refractory, vulcanized-rubbercompounds, carrying forty per cent. or more of refractory mineralmatter. Such compounds, whether they contain a proportion of sulphursuitable for making what is called a soft-rubber compound or a higherpercentage of sulphursuch as is used for making vulcanite-if theycontain refractory mineral matter in the above-described proportions,are suitable for this use, whatever the chemical constitution of therefractory mineral matter may be. I, however, prefer for this purpose,as I believe it has a higher modulus of expansion under thermoticinfluences, the compound described in Letters Patent No. 232,974,, forelastic packing, the preferred composition of which, as described insaid patent, being twenty to fifty-five per cent of diatomaceous silicaor infusorial earth, thirtyfive to fifty per cent. of rubber, and fiveto twenty per cent of sulphur, this elastic packing, for the purposes ofuse with this airvalve, preferably containing forty per cent. or more ofrefractory mineral substance.

In use the packing is set by the screw-plug so that its seating surface0 comes in contact with the raised seat B when the packing is expandedby heat, or, in other words, when steam, hot water, or hot air, or otherheated medium enters the valve chamber C6 and causes the valve to beelongated by the heat imparted to it, and upon the cooling of the valveand its body or case the packing is contracted and becomes enoughshorter in length to remove its seat surface from contact with thevalve-seat B, so that an opening is provided for the, escape of cooledair or any other medium which it is desired shall be permitted to escapethrough the valve before the valve is actuated by the application ofheat.

In Fig. at I have shown a different form of valve, the valve beingtubular in form, instead of solid, and having a hole in continua- IOOtion of the hole a Itis fastened to the diaphragm, tightly fitting thehole or recess formed therein, and it is elongated and shortened byvariation in temperature thereof in relation to this diaphragm. Thiscauses its end next the adjusting plug or screw to become one seat ofthe valve and the surface of the adjusting plug or screw the other seatof the valve.

It Will be observed that this construction of valve is very compact andcheap; also, that the valve is set by bringing the adj usting screw orplug against it to close it when it is lengthened by heat, so that uponits contraction it operates to automatically open the valve, and thisinsures its automatic action by variation in temperature after thepacking has been once set.

I would say, also, that the invention can be applied to any valve-trapor similar device subject to change in temperature and having a passagewhich it is desired to open and close.

Having thus fully described my invention,

I claim and desire to secure by Letters Patent 2 of the United States-An improved automatic air-valve for steamradiators, &c., of the classknown as rodtraps, in which the expansion valve-stem c011- trolled bysteam heat is composed of the 3 crude, burned, refractory, elasticcompound containing forty per cent. or more of refractory mineralsubstance in conjunction with vulcanizable gum, and known to commerce ascompression-packing, for facing steam- 3 valve seats and joints,substantially as and for the purpose described.

CHARLES JENKINS. \Vitnesses:

F. F. RAYMOND, 2d, J. M. DOLAN.

